Article-assembling apparatus



June 2, 1959 E. D. HANSON ARTICLE-ASSEMBLING APPARATUS Filed May 2'7.1954 3 Sheets-Sheet l Q Q\.\ NS mmit .25 w H .396 xmqzl 3:? N I IEQG 4.3 F! Ifib: m N 2 I25 m INVENTOR. E. 0. HANSON ATTORNEY June 2, 1959 E.D. HANSON I 2,888,735

ARTICLE-ASSEMBLING APPARATUS SSh eetS-Sheet 2 Filed May 27, 1954INVENTOR. E. D. HANSON BY ,4 TTORNEY June 2, 1959 Filed May 27. 1954 E.D. HANSCN ARTICLE-ASSEMBLING APPARATUS 3 Sheets-Sheet 3 i I56 93INVENTOR. 37 llllilllllllllllllll 0 Q I/ ARTICLE-ASSEMBLING APPARATUSEstyle D. Hanson, Baltimore, Md., assignor to Western Electric Company,Incorporated, New York, N.Y., a corporation of New York Application May27, 1954, Serial No. 432,767

7 (Ilairns. (Cl. 29-253) This invention relates to article-assemblingapparatus, and more particularly to apparatus for positioning oneelement of an assembly in pressing contact with another element of theassembly.

In the manufacture of cartridge-type, point contact transistors, one ofthe critical operations involves the assembly of a crystal Wafer withinthe cartridge. The crystal wafer is pressed against the tips of twospaced electrodes which are designed to bear resiliently upon itssurface. It is essential that the wafer be located precisely at apredetermined position within the cartridge, in order to. obtain apredetermined contact pressure between the surface of the crystal waferand the electrodes.

It is an object of this invention to provide new and improvedarticle-assembling apparatus.

, It is another object of this invention to provide new and improvedapparatus for positioning one conductive element of an assembly inpressing contact with another conductive element of the assembly.

Article-assembling apparatus illustrating certain features of theinvention may include a ram positioned to engage the first-mentionedelement, a fluid-actuated cylinder for operating the ram, means forapplying a fluid under pressure to the cylinder to cause the ram to movethe first-mentioned element into initial contact with the other element,means for interrupting the flow of fluid from the supply means to thecylinder simultaneously with the completion of the initial contact, andmeans operated subsequently for injecting a predetermined amount offluid into the cylinder to cause the ram to increase the contactpressure between the elements to a predetermined amount.

A complete understanding of the invention may be obtained from thefollowing detailed description of an apparatus forming a specificembodiment thereof,-when read in conjunction with the appended drawings,in which:

- Fig. 1 is a partial section of a cartridge-type, point contacttransistor, with parts thereof broken away for clarity; Fig. 2 is a planview of an article-assembling apparatus, with parts thereof broken awayfor clarity;

' Fig. 3 is a vertical section taken along line 3-3 of Pi 2;

Fig. 4 is an enlarged, fragmentary section taken along line 4-4 of Fig.2, with parts thereof broken away for clarity;

Fig. 5 is an enlarged, fragmentarysection taken along line 5-5 of Fig.2;

Fig. 6 is a schematic representation of a hydraulic system forming partof the apparatus;

Fig. 7 is a schematic representation of an electrical control circuitforming part of the apparatus," and J Fig. 8 is a diagram of thesequence of operation of certain switches forming part of the apparatusduring one complete cycle. a

Referring now to Fig. 1, there is illustrated a conventionalcartridge-type, point contact transistor which includesatubular, metalcartridge 11. Positioned within ice one end of the metal cartridge 11 isa plug assembly designated generally by the numeral 12 comprising twospaced, rigid, metal pins 14 and 15 fixedly disposed in a cylindricalplug 16 of insulating material. The plug 16 is designed to fit closelywithin one end of the tubular, metal cartridge 11 and is held fixedly'therewithin by internally projecting, annular crimped portions 18 and19 formed in the cartridge.

The inner ends of the pins 14 and 15 carry electrodes 20 and 21,respectively, which are formed of resilient wire. In the finishedtransistor the electrodes 20 and 21, conventionally referred to as theemitter and the collector, respectively, are spaced apart about 2 or 3mils at their tips which bear resiliently on the surface of a smallwafer 22 of a semi-conducting crystal material, such as germanium,having a surplus of conduction electrons (e.g. type N germanium). Thecrystal wafer 22 is soldered onto a cylindrical metal base contact 23,which is designed to be force-fitted within the open end of thecartridge 11 and to make electrical contact with the cartridge.

The apparatus shown in Fig. 2 is designed to adjust the position of thebase contact 23 and the crystal wafer 22 within the cartridge 11 so asto obtain a predetermined contact pressure between the surface of thecrystal Wafer and the electrodes 20 and 21. This apparatus includes acircular, metal turret mounted rotatably on a vertical pedestal 32 (Fig.3) for rotation in a horizontal plane. Intermittent rotation of theturret 30 is accomplished by means of an indexing mechanism designatedgenerally by the numeral 34 including a drum type cam 35 driven througha gear reduction unit 36 by a constant speed, electric motor 3'7. Thecam 35 is provided with a cam slot 39 arranged to engage successivelyeach of a series of eight cam rollers 40-40 depending from and spacedequidistantly around the underside of the turret 30. Once during eachcycle of revolution of the cam 35, the slot 39 engages one of the camrollers 40-40 and indexes the turret 30 through an angle of 45.

Mounted fixedly on the turret 30 is an annular, metal support member 42(Figs. 3 and 5) provided with eight equally spaced, generallycylindrical sockets 45-45, each of which is adapted to receive andretain a tubular cartridge 11 having a plug assembly 12 mounted fixedlywithin one end thereof. Each of the sockets 45-45 is provided with alongitudinal extending slotway 47 which serves to orient and hold thepins 14 and 15 of the plug assembly 12 in a generally vertical plane andpermits the passage through the socket of the pin 15 which is bent andextends outwardly beyond the periphery of the cartridge 11. Mounted inthe wall of each of the sockets 45-45 is a spring-pressed detentdesignated generally by the numeral 50, which is adapted to releasablyengage the annular, crimped portion 19 formed in the wall of thecartridge 11. Mounted fixedly on the turret 3t) and within the annularmetal support member 42 is an annular, flanged, metal backing member 52(Fig. 5), the outer surface of which is spaced a short distance from theinner surface of the support member 42. The backing member 52 isprovided with eight slots 54-54, each of which is" slot 54 withoutcontacting the sides thereof. Mounteddirectly behind each of the slots54-54 in the backing member 52 is a leaf-type, spring contactor 60arranged to engage and make electrical contact with the outer end of thepin 14 on the plug assembly 12. The contactor 60 is electricallyinsulated from the metal turret 30, the metal support member 42 and themetal backing member Y52, and forms part of an electrical controlcircuit which will hereinafter be described in detail.

Positioned adjacent to the turret 30 is a hydraulic cylinder designatedgenerally by the numeral 67. Slidably mounted within the cylinder 67 isa spring-biased piston 69 operatively connected to a ram 70. The freeend of the ram 70 is cylindrical and has a diameter slightly less thanthe internal diameter of a tubular cartridge 11. After each indexingmovement of the turret 30 a socket 45, having inserted therein acartridge 11 provided with a plug assembly 12, is positioned adjacent tothe hydraulic cylinder 67. In this position the longitudinal axes of thecartridge 11 and the ram 70* are aligned. The piston 69 is operable toan extended position to advance the ram 70 from right to left, as viewedin Fig. 5, toward and into the end of the cartridge 11, which is heldimmovably in the socket 45 against the backing member 52. The advancemovement of the ram 70 is effected and controlled by the admission ofhydraulic fluid under pressure through an entry port 72 provided in thecylinder 67. A compression spring 74 serves to return the piston 69 toits normal inoperative position when the fluid pressure is released,whereby the ram 70 is retracted.

Before a cartridge 11 positioned in the socket 45 is indexed intoposition adjacent to the hydraulic cylinder 67, a base contact 23carrying a crystal wafer 22 is prepositioned partially within the end ofthe cartridge, as shown in Fig. 5. Subsequent operations of the ram 70,when the cartridge 11 is positioned adjacent to the operating station,are designed to force the base contact 23 and the crystal wafer 22 intothe cartridge to a position wherein a predetermined contact pressure isobtained between the surface of the crystal wafer and the electrodes 20and 21.

Referring now to Fig. 6, there is shown schematically a hydraulic systemfor operating the ram 70. The system includes a reservoir 75 having anoutlet 76 connected to the intake of a hydraulic pump 78 which is drivenby an electric motor 80. The pump 78 discharges into an accumulator 82of conventional design, which maintains a supply of hydraulic fluidunder a substantially constant pressure. Associated with the accumulator82 is a pressure sensitive switch 83, which controls the operation ofthe electric motor 80 in a manner such as to maintain the pressure ofthe hydraulic fluid within the accumulator substantially constant at apreselected value.

Communicating with the accumulator 82, in series with valves 90 and 91,is a hydraulic line 92 which is normally in communication with the port72 in the cylinder 67 through a solenoid-operated, three-way valve 93controlled by a solenoid 95. The valve 90 is a manually operated,normally-open, flow control valve and the valve 91 is a normally closedgate valve controlled by a solenoid 96. interposed between the port 72in the cylinder 67 and the three-way, solenoid-operated valve 93 is avariable-volume, auxiliary cylinder 100 (Figs. 2, 4 and 6). Slidablymounted within the auxiliary cylinder 100 is a piston 102 (Fig. 4)provided with a piston rod 103 pivotally connected to the free end of anarm 104 by means of a pin 105. The arm 104 is fulcrumed by means of apin 107, which pivotally connects it to the upper end of an uprightsupport bracket 110.

Movement of the piston 102 in a downward direction, as viewed in Fig. 4,may be effected by the energization of a pull-type solenoid designatedgenerally by the numeral 112 having a movable plunger 114 which ishin'gedly connected to the arm 104 at a point intermediate of its ends.A compression spring 115 positioned on the cylinder 100 returns thepiston 102 to its normal, raised position when the solenoid 112 issubsequently de-energized. The latter position is determined by theposition of an adjustable stop 120, against which the lever arm 104 isnormally engaged. The stop 120 is part of a conventional micrometerhead, indicated generally at 122, which is supported by a bracket 123.The position of the stop 120 may be adjusted vertically by manuallyrotating an internally threaded collar 125. This arrangement permitsvery precise adjustments to be made in the volume of the auxiliarycylinder 100, the volume being dependent upon the normal position of thepiston 192 when the solenoid 112 is de-energized.

Referring again to Fig. 6, the cylinder 67 may be disconnected from thehydraulic line 92 and connected to the reservoir by means of thethree-way, solenoid-operated valve 93. Although the valve 93 normallyconnects the line 92 to the cylinders 67 and 100, energization of itsassociated solenoid operates the valve 93 to permit the cylinder 67 todischarge the fluid therein into the reservoir 75 at atmosphericpressure as the compression spring 74 returns the piston 69 to itsinoperative position.

Shown schematically in Fig. 7 is an electrical circuit for controllingthe operation of the apparatus. The solenoid 96 of the solenoid-operatedvalve 91 is connected in series with a normally closed contact 132 of asensitive relay 134 and a normally open contact 136 of a camoperatedswitch 137 (Fig. 2) across bus lines 140 and 141 energized from asuitable source of potential (not shown). The solenoid 112 is connectedin series with a normally open contact 143 of a cam-operated switch 144(Fig. 2) across the bus lines 140 and 141. Connected in parallel withthe series arrangement of the contact 143 and the solenoid 112 is aseries arrangement of the solenoid 9S and a normally open contact 146 ofa cam-operated switch 147 (Fig. 2).

The switches 137, 144 and 147 (Fig. 2) are operated in a predeterminedtime sequence by means of cams 150, 151 and 152, respectively. The cams150, 151 and 152 are keyed upon a shaft 155, which is driven through thegear reduction unit 36 and a suitable gear train designated generally bythe numeral 156 by the electric motor 37. The sequence of operation ofthe switches 137, 144 and 147 by the cams 150, 151 and 152 during onecomplete cycle of operation is illustrated graphically in Fig. 8. Thewavy lines represent portions of the cycle during which the respectiveswitches 137, 144 and 147 are closed.

Also illustrated in Fig. 8 for reference is the portion of the cycleduring which the indexing of the turret is accomplished by the cam 35.Referring again to Fig. 7, the sensitive relay 134 has a solenoid 160which forms part of a normally incomplete circuit including a D.-C.supply, indicated schematically at 162, connected in series therewith.The positive terminal of the D.-C. supply 162 is connected to thecontactor 60, which is engaged by the pin 14 on the plug assembly 12when a cartridge 11 with a plug assembly 12 therein is positionedproperly in the socket 45. The negative terminal of the D.-C. supply 162is connected through the solenoid 160 to the base contact 23 and thecrystal wafer 22, and to a common ground at 163. The groundingconnection is made preferably through the metal support member 42 andbacking member 52 with which the tubular cartridge 11 makes contact whenengaged properly within the socket 45. The circuit, including thesolenoid 160 of the sensitive relay 134, is completed when the crystalwafer 22 makes contact the electrode 20 (emitter), which contact has arectifying action permitting a flow of current sutficient to operate thesensitive relay 134.

Operation Let it be assumed that the apparatus is already in operationwith the electric motor 37 energized, and that it is at the beginning ofa cycle of operation. The turret 30, which has just completed anindexing movement, supports a cartridge 11 having a plug assembly 12 inposition adjacent to the ram 70 and cylinder 67. As shown in Fig. 5, thecartridge 11 has a base contact 23 carrying a crystal wafer 22 receivedpartially within its unsupported end. The base contact 23 and thecrystal wafer 22 have been prepositioned within the open end of thecartridge 11 by suitable loading means (not shown).

Immediately after the start of the cycle of operation, the cam 150actuates the switch 137 to close its associated contact 136. When thecontact 136 closes, the solenoid 96 is energized to operate the valve 91to its open position. The opening of the valve 91 admits hydraulic fluidunder a predetermined pressure to the cylinder 67 through the hydraulicline 92 and the three-way, solenoid-operated valve 93. T he hydraulicfluid also fills the auxiliary cylinder 100.

As the hydraulic fluid enters the cylinder 67 it advances the piston 69and the attached ram 70 from right to left, as viewed in Figs. 2, and 6,whereby the ram engages the ba'se contact 23 and forces it further intothe cartridge 11 until the surface of the crystal wafer 22 makes initialcontact with the emitter electrode 20. Simultaneously with the making ofthe contact between the emitter electrode 20 and the surface of thecrystal wafer 22, the circuit including the D.-C. supply 162 and thesolenoid 160 of the sensitive relay 134 is completed to energize thesolenoid 160. When the solenoid 160 is energized, it opens the contact132, which in turn deenergizes the solenoid 96 to immediately close thevalve 91. Thus, the forward movement of the ram 70 is stoppedimmediately upon the making of the contact between the emitter electrode20 and the surface of the crystal wafer 22.

Subsequently, the cam 15% permits the contact 136 to reopen, after whichthe cam 151 actuates the switch 144 to close its normally open contact143 and connect the solenoid 112 across the supply lines 144) and 141.When the solenoid 112 is energized, its associated plunger 114 is pulleddownwardly, whereby the arm 104 pivots counterclockwise, as viewed inFigs. 4 and 6, to force the piston 102 downwardly. The downward strokeof the piston 102 results in the injection of a predetermined volume offluid into the cylinder 67. This predetermined additive amount of fluidfrom the auxiliary cylinder 100 causes the ram '70 to advance a smallpredetermined distance to position the base contact 23 and the crystalwafer 22 accurately so that the electrodes 20 and 21 bear resiliently onthe surface of the crystal Wafer with a predetermined contact pressure.

The cam 151 subsequently causes the contact 143 to resume its normallyopen condition to de-energize the solenoid 112. Thereupon the piston 102of the cylinder 100 is returned to its normal, raised position by thecompression spring 115 mounted in the cylinder. Immediately thereafterthe cam 152 operates its associated switch 147 to close its normallyopen contact 146, whereby the solenoid 95 is energized to operate thethree-way valve 93 so as to connect the cylinders 67 and 100 to thereservoir 75. The compression spring 74 returns the piston 69 to itsnormal inoperative position at the right hand end of the cylinder 67,whereby the ram 70 is retracted and the fluid previously contained inthe cylinder is discharged at atmospheric pressure into the reservoir75.

Subsequently, the earn 152 permits the contact 146 of the switch 147 toreopen, thereby de-energizing the solenoid 95 to return the three-wayvalve 93 to its normal position wherein it connects the hydraulic line92 to the cylinders 67 and 100. With the ram 711 retracted, the turret31 is indexed during the remaining portion of the cycle when the camslot 39 on the drum-type cam 35 engages the next cam roller 40 on theunderside of the turret. With the cycle completed, another cartridge 11,having a base contact 23 and crystal wafer 22 prepositioned so as to bepartially received within the end of the cartridge, is positionedopposite the ram 70 and the cylinder 67 in readiness "for thenext'cycle'ofoperationed adjacent to the first-mentioned element, afluid-.

actuated cylinder for operating the ram, means for supplying a fluidunder pressure to the cylinder to cause the ram to move saidfirst-mentioned element into initial contact with the other element,means for interruptingthe flow of fluid from the supply means to thecylinder simultaneously with the completion of said initial contact, anauxiliary cylinder having a predetermined volumetric capacity, means forfilling the auxiliary cylinder with" fluid, and means'operatedsubsequently for injecting the predetermined amount of fluid from theauxiliary cylinder into the first-mentioned cylinder whereby theadditional fluid thus introduced causes the ram to increase the contactpressure between the elements to a predetermined value.

2. Apparatus for assembling a wafer of a semi-conductive crystal withinone end of a tubular shell having a resilient, point contact electrodemounted fixedly within.

the other end thereof, which comprises a ram positioned adjacent to thecrystal wafer, a fluid actuated cylinder for operating the ram, meansfor supplying a fluid under' pressure to the cylinder to cause the ramto move the crystal wafer into initial electrical contact with theresilient electrode, electrically actuated means responsive to theestablishment of said contact for interrupting immediately the flow offluid from the supply means to the cylinder, an auxiliary cylinderhaving a predetermined volumetric capacity, means for filling theauxiliary cylinder with fluid, and means operated subsequently for in-'jecting the predetermined amount of fluid from the auxiliary cylinderinto whereby the adidtional fluid thus introduced causes the ram toincrease the contact pressure between the electrode and the crystalwafer by a predetermined amount.

3. Apparatus for assembling a wafer of a semi-conductive crystal withinone end of a tubular shell having a resilient, point contact electrodemounted fixedly within the other end thereof, which comprises a rampositioned adjacent to the crystal wafer, a fluid actuated cylinder foroperating the ram, means containing a supply of fluid, a conduitcommunicating with the fluid supply means and the cylinder, a valveinterposed in the conduit between the fluid supply means and thecylinder, means for operating the valve to admit a flow of fluid intothe cylinder to operate the ram to move the crystal wafer into initialelectrical contact with the electrode, electrically actuated meansresponsive to the establishment of said contact for closing the valveimmediately, and means actuated subsequently for injecting anadditional, predetermined volumetric amount of fluid into thefirstmentioned cylinder whereby the additional fluid thus introducedcauses the ram to move the crystal wafer further into the shell by apredetermined distance suflicient to increase the contact pressurebetween the electrode and the crystal wafer by a predetermined amount.

4. Apparatus for assembling a wafer of a semi-conductive crystal withinone end of a tubular shell having a resilient, point contact electrodemounted fixedly within the other end thereof, which comprises a rampositioned adjacent to the crystal wafer, a fluid actuated cylinder foroperating the ram, means containing a supply of fluid under pressure, aconduit communicating with the fluid supply means and the cylinder, avalve interposed in series with the conduit for disconnecting thefirst-mentioned cylinderthe fluid supply means from the cylinder, anauxiliary, adjustable volume, fluid cylinder communicating with theconduit at a point between the first-mentioned cylinder and the valve,means for adjusting the volumetric fluid capacity of the auxiliarycylinder to a preselected amount, means for operating the valve to admitfluid under pressure from the supply into the first-mentioned cylinderand the auxiliary cylinder, whereby said fluid fills the auxiliarycylinder entirely and operates the ram to move the crystal into initialelectrical contact with the electrode, electrically actuated meansresponsive to the establishment of said contact for closing the valveimmediately to momentarily stop the movement of the ram and the crystal,and means for subsequently injecting additionally the predeterminedvolume of fluid contained in the auxiliary cylinder into thefirst-mentioned cylinder whereby the additional fluid thus introducedcauses the ram to move the crystal Wafer further into the shell by apredetermined distance suflicient to increase the contact pressurebetween the electrode and the water by a predetermined amount.

5. Apparatus for assembling a water of a semi-conductive crystal withinone end of a tubular shell having a resilient, point contact electrodemounted fixedly within the other end thereof, which comprises a ram, afluid actuated cylinder for operating the ram, a rotatable turret, meansfor detachably mounting spacedly around the turret a plurality of suchtubular shells, each having a crystal Wafer prepositioned partiallywithin one end thereof, means operable periodically for indexing theturret to position one at a time the ends of the shells containing theprepositioned crystal wafers adjacent to the fluid operated ram, meansoperated each time a shell is positioned adjacent to the ram forsupplying a fluid under pressure to the cylinder to cause the ram tomove the prepositioned crystal water into initial electrical contactwith the electrode fixedly mounted within the opposite end of the shell,electrically actuated means responsive to the establishment of saidcontact for inter rupting immediately the flow of fluid from the supplymeans, and means actuated subsequently for injecting a predeterminedadditional quantity of fluid into the cylinder whereby the additionalfluid thus introduced causes the ram to move the crystal wafer toincrease the contact pressure between the resilient electrode and thecrystal water by a predetermined amount.

6. Apparatus for assembling a wafer of a semi-conductive crystal withinone end of a tubular shell having a resilient, point contact electrodemounted fixedly within the other end thereof, which comprises a ram, ahydraulically actuated cylinder for operating the ram, means containinga supply of hydraulic fluid under pressure, a conduit communicating withthe fluid supply means and the cylinder, a normally closed valveinterposed in series with the conduit and normally disconnecting thefluid V supply means from the cylinder, an auxiliary cylindercommunicating with the conduit at a point between the first-mentionedcylinder and the valve, a rotatable turret, means for detachablymounting spacedly around the turret a plurality of such tubular shells,each having a crystal wafer prepositioned partially within one endthereof, means operable periodically for indexing the turret to positionone at a time the ends of the shells containing the prepositionedcrystal wafer adjacent to the hydraulically operated ram, means foroperating the valve each time a shell is positioned adjacent to the ramto admit fluid under pressure into the first-mentioned cylinder and theauxiliary cylinder, whereby said fluid fills the latter entirely andoperates the ram to move the crystal into initial electrical contactwith the electrode, electrically actuated means responsive to theestablishment of said contact for closing the valve immediately tomomentarily stop the movement of the ram and the crystal, and means forsubsequently injecting a predetermined additional volume of fluid fromthe auxiliary cylinder into the first-mentioned cylinder whereby theadditional fluid thus introduced causes the ram to advance the wafer apredetermined distance suflicient to increase the contact pressurebetween the electrode and the crystal water by a predetermined amount.

7. Article-assembling apparatus for positioning one element of anassembly in pressing contact with another element of the assembly, whichcomprises a ram connected operatively to the first-mentioned element, afluid actuated cylinder for operating the ram, means for supplying afluid under pressure, a conduit communicating with the fluid supplymeans and the cylinder, a valve interposed in series with the conduitfor disconnecting the fluid supply means from the cylinder, an auxiliarycylinder communicating with the conduit at a point between thefirst-mentioned cylinder and the valve, means for operating the valve toadmit a flow of fluid into both of the cylinders whereby the fluid fillsthe auxiliary cylinder to its eflective capacity and operates the ram tomove the first-mentioned element into initial contact with the otherelement, means responsive to the establishment of said initial contactbetween the elements for closing the valve immediately, and meansoperated subsequently for injecting the predetermined additional amountof fluid from the auxiliary cylinder into the first-mentioned cylinderwhereby the additional fluid thus introduced causes the ram to increasethe contact pressure between the elements to a predetermined value.

References Cited in the file of this patent UNITED STATES PATENTS2,072,087 Dewar Mar. 2, 1937 2,503,837 Ohl Apr. 11, 1950 2,649,560 BlairAug. 18, 1953 2,757,440 Carman Aug. 7, 1956

